Count values in lookup table based on filter in lower table

[amartino44]

Hello. I have a lookup table. I would like to count the number of customers, based on whether or not they had invoices with a PAID status (so there would be an invoice period, some don't have invoices, and then it would only count if a corresponding column said "paid"). Gracias. This is my current formula but it just counts invoices period attached to each customer. Helpy me.


=COUNTX(RELATEDTABLE('Big Invoices My Baby'),'Big Invoices My Baby'[IV Falcon Invoice Num])